Weft bobbin stand

ABSTRACT

There is disclosed, for use with looms in which the weft supply remains outside the shed, a wheeled weft bobbin stand including a weft bobbin creel, weft thread brakes, and intermediate weft thread storage devices.

United States Patent I Bucher WEF T BOBBIN STAND [72] Inventor: RobertBucher, Winterthur, Switzerland [73] Assignee: Sulzer Brothers terthur,Switzerland [22] Filed: Dec. 4, 1970 [21] Appl. No.: 95,396

Related US. Application Data [63] Continuation of Ser. No.756,900,-Sept. 3,

. 1968,abandoned.

Limited, Win- [30] Foreign Application Priority Data Sept. 6, 1967Switzerland ..l2479/67 [51] Int. Cl. ..B65h 49/02, D02h 1/00, D03j 5/08[58] Field of Search....242/131, 131.1; 139/122, 128

[451 Sept. 26, 1972 [56] References Cited UNITED STATES PATENTS2,527,700 10/1950 Bryant ..242/l3 1.1 3,168,911 2/1965 Pfarrwaller eta1. 139/122 3,276,484 10/1966 Bucher ..139/l22 Primary Examiner-LeonardD. Christian Attorney-Pennie, Edmonds, Morton, Taylor & Adams 1 57]ABSTRACT There is disclosed, for use withlooms in which the weft supplyremains outside the shed, a wheeled weft bobbin stand including a weftbobbin creel, weft thread brakes, and intermediate weft thread storagedevices.

3 Claims, 5 Drawing Figures PAIENTEDszrzs @912 Inventor.- Robert Buchersum 2 OF 3 y w I M Wax- .7 74,, g m

TTORNEYS WEFT BOBBIN STAND This application is a continuation of Ser.No. 756,900, filed Sept. 3, 1968 and now abandoned.

The present invention pertains to a movable weft thread bobbin stand forlooms of the type in which the weft thread supply is retained outsidethe shed, and

more particularly for looms of this type in which wefts of differentyarn types or colors are employed, successive wefts being pulled off theend of weft bobbins of the various types or colors of yarn for pickingthrough the shed in a specified sequence and being picked through theshed after passing through intermediate weft thread storage devices onwhich there is stored'at least the length of thread necessary for onepick.

ln known looms the weft bobbin creel is disposed in the vicinity of theweaving plane on the picking side of the loom, either vin fixed positionor swingably on a hinged supporting frame. This construction makes itdifficult to obtain access to certain portions of the loom such as theheddle driving mechanism, the picking mechanism, the yarn feedingdevice, weft tensioner and pull-back mechanism, the heddle reversingmechanism and, especially in looms employing plural wefts, the weftchange mechanism.

It has been proposed, in the copending application of ErwinPfarrawallerentitled WEPT BOBBIN CREEL, Ser. No. 752,714 filed Aug. 14, 1968, nowUS. Pat. No. 3,526,253 assigned to the assignee hereof, to support theweft thread bobbins on a creel affixed to the loom frame in a positionabove the picking mechanism of the loom. In the apparatus disclosed inthat application, the bobbins are disposed in one or more superposedapproximately circular arrays about a vertical axis on inwardly directedstub shafts. The threads pulled off the ends of the bobbins pass throughthread guiding eyes in the vicinity of the axis of the creel and thencedownwardly through a hollow hub out of the creel and through weft threadbrakes.

Intermediate weft thread storage devices have moreover been proposed,especially for use in looms operating at high picking rates; Such adevice pulls the thread from the supply bobbin at a speed low comparedto the speed at which the weft is picked through the shed and maintainson a drum a length of thread sufficient for at least one pick, so thatwhen the pick occurs the thread can be pulled off the end of the drum atthe very high speed required by the actual picking operation. Apparatusof this kind is disclosed in the copending application of ErwinPfarrwaller entitled WEFT THREAD SUPPLY APPARATUS FOR GRIPPER SHUTTLELOOMS, Ser. No. 584,131, filed Oct. 4, 1966, and assigned to theassignee hereof, now US. Pat. No. 3,411,548.

Provision on the loom of a weft bobbin creel and of intermediate weftthread storage apparatus however restricts access to various parts ofthe loom structure on the picking side thereof. The present applicationis intended to surmount this difficulty. It provides a movable weftbobbin stand which includes a creel and intermediate weft thread storageapparatus through which the weft threads pass from the bobbins to thepicking mechanism of the loom.

The apparatus of the invention can be employed with looms not havingintermediate weft thread storage apparatus in order to fit them forhigher picking rates without necessarily removing therefrom the originalweft bobbin supporting apparatus, which retains its utility for weavingat lower picking rates.

When cloth is to be woven with wefts of plural colors or yarn types,there are customarily provided two weft bobbins for each color. Whilethread is drawn from one bobbin of each color, the second bobbin of thatcolor is held in reserve, the outer end of its thread being knotted tothe inner end of the thread on the bobbin currently in use, so that whenthe first bobbin is exhausted, the thread will be automatically drawnfrom the second without interruption of the weaving process. Afour-color loom therefore customarily requires at least eight weftbobbins, making up an assembly of substantial weight and bulk.

When a loom is shifted from weaving of one type .of cloth to another,all of the weft bobbins must customarily be replaced. The weft threadbobbin stand of the invention possesses in this respect the advantagethat such a stand can be prepared in advance for a new type of cloth.When the type of cloth to be woven is to be changed, the weft bobbinstand previously employed can be replaced with a fresh one having thedesired weft bobbins suitably mounted therein, with minim um loss ofweaving time.

The bobbin stand of the invention does not need to be positioned withhigh accuracy with respect to its loom, the essential requirement beingsimply that the threads from the several weft bobbins or weft bobbinpairs shall pass freely from exit guide eyes on the stand into anentrance eye or eyes on the loom.

The stand of the invention may include for each weft thread (e.g. foreach pair of weft thread bobbins) a weft thread brake, which may be ofany suitable type. These brakes are disposed downstream of the bobbins,in the sense of weft thread motion, and their function is to holdconstant the tension of the threads as pulled from those bobbins and toprevent premature withdrawal of coils therefroml In a preferredembodiment thereof, the bobbin stand of the invention includes for eachof the separate typesor colors of weft to be woven into the cloth, oralternatively for each group of such threads to be simultaneously pickedthrough the shed as by means of a common shuttle, a separateintermediate weft thread storage device having its own exit guide eyedisposed adjacent the corresponding inlet eye of the loom.

The drive or drives for the intermediate weft thread storage devices aredesirably disposed in the stand immediately adjacent those devices, eachof those devices including desirably its own automatic control, such asthe photoelectric control disclosed in the copending application Ser.No. 584,131, now Pat. No. 3,411,548 whereby there is maintained instorage in each of those devices a length of thread between a minimumand a maximum. The intermediate weft thread storage devices are drivenby an electric motor or motors connected via a flexible cable to anelectric power receptacle on the loom.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be furtherdescribed in terms of a non-limitative exemplary embodiment thereof andwith reference to the accompanying drawings, in which:

FIG. 1 is an end elevation of a loom with a weft bobbin stand inaccordance with the invention, the loom being seen from the cloth endthereof;

FIG. 2 is a view in elevation at an enlarged scale of the weft bobbincreel of the stand of the invention, seen at an enlarged scale andpartially in cross-section;

FIG. 3 is a diagrammatic plan view-of the creel of FIG. 2; 1

' FIG. 4 is a view partly in vertical elevation and partly in section,illustrating an intermediate weft thread storage device which can beused in the weft bobbin stand of the invention; and

FIG. 5 is a sectional view taken on the line 2-2 of FIG. 4.

DESCRIPTION OF PREFERRED EMBODIMENT Referring to FIG. 1, the stand ofthe invention is generally indicated at l, disposed at the picking sideof a loom generally indicated at 2. In the loom, reference character 3identifies the cloth beam, the picking and catching side frame membersthereof being identified at reference characters 30 and 31. The maindrive motor 4 drives the main loom shaft through a belt connection to acombined flywheel and clutch 5. Reference character 6 identifies heddleframes for formation of a shed. The picking mechanism is indicated at 7and a gripper shuttle is shown at 9 passing through the shed to acatcher 8. One or more weft threads 23 may be simultaneously pickedthrough the shed by meansof the same shuttle. If narrower widths ofcloth are to be woven, the catching mechanism 8 may be moved backtowards the picking side, for example to the position indicated at 8a indot-dash lines. After it hasbeen picked through the shed, the shuttle isbraked to a stop in the catcher and is returned or restored a shortdistance toward the picking side of the loom in order to-compensate forirregularities in the distance required for braking. In this process theweft is similarly drawn back toward the picking side by means of athread tensioner 10. his then grasped by edge clamps not shown andcutoff on the picking side. The weft so inserted is then beaten up bythe reed and is bound into thecloth with the next shed change. The weftends initially extending beyond the edges of the cloth are tucked intothe next shed by means of tuck-in needles not shown and are beaten upwith the next weft to form a secure selvage. For achievement'of variousforms of weave the heddles 6 are driven by a dobby 11, for example ofthe card or eccentric type, which can also control the weft feeders forselection in proper order of wefts from the various pairs of weftbobbins 22 (FIG. 2) in the creel 13 of thestand 1 in FIG. 1. Accordingto the prescribed succession of weft colors, one or more wefts may bedrawn in succession from the same bobbin 22 while the other bobbins arewaiting, oralternatively the weft color or yarn type can be changed witheach pick.

In the case of high speed looms account must be taken of the fact thatthe time available for picking is a small fraction of the loom cycle.The speed of the shuttle and of the weft attached thereto is thereforehigh during their passage through the shed, whereas the end of the weftnext to be inserted is practically stationary until picking timetherefor. In order to achieve dependable operation with thisdiscontinuous motion of the wefts, one or more intermediate weft threadstorage devices 12 are provided in accordance with the invention in thestand 1, downstream (in the sense of weft thread motion) of the bobbins22 or of their respective thread-guiding eyes 24 in the creel. Theseintermediate weft thread storage devices may be of the type disclosed inthe copending application Ser. No. 584,131 now US. Pat. No. 3,411,548hereinabove referred to. A weft thread brake 24a, disposed in the stand1 between each of the eyes 24 and its intermediate weft thread storagedevice 12 serves to effect withdrawal of the weft threads in optimumfashion and with formation of a thread balloon between the bobbins 22and eye 24, for delivery at substantially constant tension through thedevices 12 and the exit guide eyes 29 of the stand to the entrance eyes32 of the loom. The devices 12 are driven by means of common motor 12a,mounted on the stand, the motor being energized via a flexible cord 12bconnecting to a power outlet on the loom. The creel 13 is fastened tothe base 27 of the stand 1 by means of a strut 14 and is so disposedthat in operating condition it is located above the thread -feedingdevices 10 of the loom at the picking side thereof. The base 27 issupported on wheels 35. As illustrated in FIG. 2, the creel 13 isdisposed above the weaving plane and is rotatable about a vertical axison a bearing 15.

Apparatus suitable to constitute each of the intermediate weft threadstorage devices 12 is shown in FIG. 4. The device of FIG. 4 includes aset of bearings generally indicated at 124 supported on the arm 123. Theball bearings proper are shown at 125. A hollow shaft 126 is supportedby means of ball bearing races from the bearing support 124. At the leftend of the shaft as seen in FIG. 4, there is provided a pulley 127mounted to turn freely on the shaft 126'. This pulley is driven by meansof a belt 128 from the drive pulley 129 of a motor 120.

The pulley 127 has affixed thereto a clutch plate 132 which cooperatesby means of a magnetic coupling with a disc 133 fixed on the shaft 126.The disc 133 includes electromagnets 134 which can be energized viabrushes 135 in a circuit including a switching device 136. When themagnetic coupling is energized, rotation of the disc 132 is imparted tothe shaft 126.

At the right end of the shaft 126 as seen in FIG. 4, there is providedan eye 137 and a bore 138 through which the weft thread 110 passes fromthe inside to the outside of shaft 126. This shaft has afiixed to itsright end a hollow conical body 139 which functions as a flyer arm. Atthe outer edge of the latter is provided a thread-feeding eye 141through which the weft thread is passed.

The shaft 126 includes an extension 142 inside the hollow cone 139. Adrum 144 is rotatably supported with respect to the shaft in this spacevia ball bearings 143. Whereas the shaft 126 with its end 142 rotates,the drum 144 is held stationary as will hereinafter be furtherexplained.

At its left end as seen in FIG. 4, the drum 144 includes a conicalenlargement 145 disposed substantially in the plane defined by therotating eye 141, which plane is normally vertical.

The right end of the drum 144 as seen in FIG. 4 is disposed within aring 146 affixed to the support arm 123 so as to leave an annular space147 between the ring and the drum. The ring 146 supports two permanentmagnets 148 as shown in FIG. 5. The cylinder 144 carries two armaturesor keepers 149 which cooperate with the magnets 148. In this way thedrum 144 is prevented from following the rotation of the elements 126,139, 141 and 142.

The support arm 123 additionally carries a light source 151 whose beam152 is obliquely incident on the drum 144. The reflected beam 153impinges on a photocell 154 which is shielded from the source 151 bymeans of a mask 150. The photocell is connected by conductors 155 to theswitching device 136; The source 151 and switching device areadditionally connected via conductors 156 and 157 to a source of voltage158.

The mode of operation is as follows: The motor 12a is energized from avoltage source 130, and rotates. Hence the hollow shaft 126 rotates withits cone 139 at uniform speed. The weft thread 110 is fed from thebobbin 22 through an eye 24 and through a thread tensioner 164 into thehollow shaft 126. The thread emerges from the shaft at 138 to passoutside the cone 139 and then through the rotating eye 141 toward theaxis of the shaft. By virtue of the rotation of the cone 139 and eye 141with respect to the stationary drum 144, a number of turns of the weftthread are built up on the drum. The arrangement is such that the turnnearest the eye 141 is formed on the conical enlargement 145 of thedrum. The drum has a polished surface so that the arriving coils causethose already wound to slip to the right in FIG. 4 and thus move ontothe cylindrical portion of the drum. After a number of revolutions havebeen executed by theshaft, several such turns will build up on thatcylindrical portion. By reason of the polished nature of the drumsurface and because of the looseness with which the turns are wound,each turn will be shifted to the right by the turn to the left of it.

During weft thread insertion, the thread 110 is pulled off thestationary drum 144 toward the right, in FIG. 4, passing through theannular space 147. As may be seen from FIG. 4, no balloon of threadforms in the region 110a. The thread then passes through an eye 29.

The average axial length 173 of the space occupied by the turns ofthread on the drum 144, which axial length is so far as possible to bemaintained constant, is desirably made of such size that the length ofthe thread wound up on the drum corresponds approximately to the widthof the cloth, i.e. to the length of one pick. If the axial length 173 ofthe space occupied by the coils on the drum extends to the right so asto cover the point 174 at which the light beam 152 is reflected, thereflected beam 153 will be interrupted, reflection occurring at most ina diffuse manner from the thread on the drum. The photocell 154 and theswitching device 136 are so adjusted that with this reduction of lightincident on the photocell, the supply of current to the magneticcoupling 132, 133, 134 is interrupted. The hollow shaft 126 and cone 139accordingly come to rest and the further accumulation of thread on thedrum 144 is temporarily halted, whereas the elements 131, 129,127 and132 continue to'rotate.

When after one or more additional picks or, according to the width ofthe cloth during the course of a sub- 1 sequent pick, enough coils arewithdrawn from the drum so as to uncover the spot 174 at which the lightbeam is incident on the drum, the photocell will again receive thereflected beam so that the magnetic coupling will be restored byoperation of the photocell 154 and switching device 136. The cone 139resumes rotation so that once more the weft thread is withdrawn from thebobbin 22 and wound up on the drum 144.

The construction of the creel itself may be of the type disclosed in thecopending application entitled WEFT BOBBIN CREEL, above-identified.Details thereof are shown in FIGS. 2 and 3. The creel includes a hub 16resting on the bearing 15 with a cam 18 on the hub and a notch 18a onthe bearing to prevent inadvertent rotation of the creel and consequenttangling of the threads. Spoke-like arms 17 are affixed to the hub 16.At the end of each arm there is provided a hinge 20 rotatable about avertical axis and having affixed thereto an arm 19 carrying at its end astub shaft 21. In operative position the arms 19 are substantiallytangential to the circular array of bobbins, so that the stub shafts 21are directed radially inward for support of the bobbins 22. In FIG. 2two adjacent bobbins 22 are shown combined into a pair with the innerend of the thread of the first bobbin connected to the outer end of thesecond. The two bobbins of each pair are disposed inside a screen 25which limits the size of the thread balloon formed from thread pulledfrom either of those spools. A partition wall 26 is disposed between thetwo spools of each pair with a pad of felt 26a on its upper edge andonto which there may be laid the connecting thread between the twospools. The screen 25 and par tition 26 are advantageously made oftransparent material and fastened to the arm 17. The thread, afterpassing through the eye 24, passes downwardly through the hub 16 and thehollow bearing 15, through a thread brake 24a and thence to theintermediate weftthread storage device 12 and to its exit eye 29 fromthe stand 1.

The stand can be fastened to the loom by means of a coupler or linkage28. Since however the only forces exerted between the stand and the loomare those produced by the weft threads being pulled from the creel,which forces are negligible, the coupling 28 can be dispensed with andthe stand can be fixed in position with respect to the loom by means ofa brake 33, operating on the wheels 35 thereof.

The invention is not limited to the embodiment disclosed. For example, aplurality of creels 13 can be provided superposed one above another.Moreover the bobbins 22 can be supported in a movable stand to bepositioned substantially in the weaving plane to the left of theintermediate weft thread storage devices 12 as seen in FIG. 1. Moregenerally, the invention includes all modifications of and departuresfrom the embodiment shown properly falling within the spirit and scopeof the appended claims. I

Iclaim:

l. A movable weft bobbin stand comprising a base, means to support aplurality of bobbins on the base, and at least one intermediate weftthread storage device mounted on the base, each of said devicesincluding a substantially cylindrical body rotatably mounted from oneend thereof whereby a weft thread wound onto said body may be pulled offthe other and thereof, means to wind a weft thread onto said body, andmeans to energize said winding means to maintain on said body a numberof turns of weft thread between limiting minimum and maximum values.

2. A movable weft bobbin stand according to claim 1 5 including wheelsfor support of said base.

3. A movable weft bobbin stand according to claim 2 including a brakeoperating on the wheels thereof.

I P0405) UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PatentNo. 3,693,90u Dat September 26. 1972 r Inventor(s) It is certified thaterror appears iii the above-identified patent and that said LettersPatent are hereby corrected as shown below:.

r Column 3, line 13, for "2-2" substitute -VV--. Column 6, line 68, for"and" substitute "end".

Signed and sealed this 20th day of February 1973 "(SEAL1 Attest:

EDWARD M.PLETCHER,JR. ROBERT GOTTSCHALK Attes'ting Officer Commissionerof Patents

1. A movable weft bobbin stand comprising a base, means to support aplurality of bobbins on the base, and at least one intermediate weftthread storage device mounted on the base, each of said devicesincluding a substantially cylindrical body rotatably mounted from oneend thereof whereby a weft thread wound onto said body may be pulled offthe other and thereof, means to wind a weft thread onto said body, andmeans to energize said winding means to maintain on said body a numberof turns of weft thread between limiting minimum and maximum values. 2.A movable weft bobbin stand according to claim 1 including wheels forsupport of said base.
 3. A movable weft bobbin stand according to claim2 including a brake operating on the wheels thereof.